Apparatus for the connection by setting of collectors on water-boxes of heat exchangers

ABSTRACT

Apparatus for the connection by crimping or clamping of collectors on water-boxes of heat exchangers is characterized in that parts of the collector and the water-box are surrounded by an electrically conductive or magnetically responsive metallic belt or strip which is then submitted to at least one high electromagnetic pulse. The device comprises a support on which is placed the water-box, a collar the inner walls of which are shaped correspondingly to the water-box, at least one induction coil connected to a pulse generator and surrounding said collar.

[451 Apr. 23, 1974 Harvey......... Ferguson ABSTRACT 8 Claims, 15Drawing Figures 9/1971 Turner.........

Primary Examiner-Richard J. l-lerbst Attorney, Agent, oFFi rm-Dvvig htH. Smiley; lmire and Smiley Apparatus for the connection by crimping orclamping of collectors on water-boxes of heat exchangers ischaracterized in that parts of the collector and the water-box aresurrounded by an electrically conductive 821d 26/14 or magneticallyresponsive metallic belt or strip which is then submitted to at leastone high electromagnetic pulse. The device comprises a support on whichis placed the water-box, a collar the inner walls of which are shapedcorrespondingly to the water-box, at least one 72/56 induction coilconnected to a pulse generator and surrounding said collar.

1 wh t/ k l a United States Patent Chartet APPARATUS FOR THE CONNECTIONBY SETTING OF COLLECTORS ON WATER-BOXES OF HEAT EXCHANGERS [76]Inventor: Andre Chartet, 2bis Avenue du Chateau, Meudon(Haute-de-Seine), France [22] Filed: Apr. 10, 1972 [21] Appl. No.:242,388

Related US. Application Data [62] Division of Ser. No. 94,237, Dec. 1,1970.

[52]. US. [51] Int. [58] Field of Search.........

[56] References Cited UNITED STATES PATENTS 3,431,625 3/1969 Schenk eta1. 3,439,403 4/1969 Lippmann e't 3,555,651 1/1971 Latussek et 3,571,9213/1971 Pieper........ 3,363,686 '1/196'8 Bifice'r.............

PATENTED APR 2 3 1974 SHEET 2 OF 4 PATENTEDAPRZB mm 3.805 569 sum 3 [1F4 APPARATUS FOR THE CONNECTION BY SETTING OF COLLECTORS ON WATER-BOXESOF HEAT EXCHANGERS This is a division, of application Ser. No. 94,237,filed Dec. 1, 1970.

BACKGROUND OF THE INVENTION An attempt has been made to connect heatexchanger water-boxes and collectors by crimping or clamping in order toavoid long and expensive welding or brazing operations. Up to now, theresults thus obtained have not been satisfactory because crimping orclamping of the water-box on the collector and viceversa of thecollector on the water-box causes undue stresses during the crimping orclamping operations on the fragile parts such as said water-boxes andespecially said collectors. Besides these stresses frequently areapplied in an irregular manner, often causing warping detrimental to thelife of the manufactured device.

Another disadvantage is caused by the fact that the known crimping orclamping apparatus do not allow to correctly perform such a work onangles existing on collectors and water-boxes whereby often resulting ina poor tightness.

SUMMARY OF THE INVENTION According to the invention, sections of thecollector and the water-box to be connected together are surrounded by abelt of electric conductive metal, and then said belt is submitted for avery short period about a few milliseconds to the action of at least onepulse generated by a high electromagnetic field, operating substantiallyperpendicularly to the different sections of said belt, wherebyobtaining the crimping or clamping of this belt on said collector andwater-box.

BRIEF DESCRIPTION OF DRAWINGS cation of the invention on a two fluidtubular exchanger;

FIGS. 7 and 8 are partial sectional views illustration additionalcharacteristics;

FIG. 9 is a partial perspective of a variant of embodiment;

FIG. 10 is a partial enlarged sectional view of a detail of FIG. 9;

FIG. 11 is a partial plan view along line XI-XI of FIG. 10;

FIG. 12 is a diagrammatic perspective of the shapin device according toa variant of embodiment;

FIG. 13 is a diagrammatic cross-sectional view showing the shapingdevice of FIG. 12 in the working conditions of FIG. I, and

FIG. 14 is a partial cross-sectional view illustrating another variantof embodiment.

DETAIIJED DESCRIPTION OF THE INVENTON FIG. I shows, in accordance withone embodiment of the invention, how the process of the invention is putinto practice to ensure the fixing of water-boxes on the collectors of aradiator core. On this figure the core comprises tubes 1 connected toheat dissipators 2, for example fins slipped on the tubes, or corrugatedintercalary strips placed between the tubes. The ends of this core areprovided with collectors 3 and 4 in communication with the tubes l.Water Boxes 5 and 6 are tightly secured to collectors 3 and 4respectively.

According to the invention, the material of the tubes 1, dissipators 2,collectors 3, 4'and water-boxes 5, 6 is not taken into consideration.For example the tubes 1 can be made of brass, aluminum or stainlesssteel; the dissipators 2 can be made of steel, copper or aluminum, thecollectors 3 and 4 can also be made of brass, steel, treated or nottreated, even made of synthetic material; and it is the same forwater-boxes 5, 6. The way the tubes are connected to the collectors andthe tubes to the dissipators is not taken into consideration in theembodiment of the invention actually, any usual assembling method putinto practice in technics can be applied, such as soft soldering,brazing, adhesively sticking, etc.

In the process of the invention, the core so-to-speak, i.e. the tubes 1,the dissipators 2 and the collectors 3, 4 are assembled; and to connectthe collectors to the water-boxes the method is as follows.

A field shaping collar 7 is prepared preferably made of copper withberyllium and the inner wall 7a of said collar is shaped to have a formcorresponding in section to the parts of collectors and water-boxes tobe joined together. If the the collectors and water boxes arerectangular with slightly rounded angles then the inner wall 7a is madein a corresponding way. If the collector and- /or the water-box showssome recesses or projections then in the same way the wall 7a is shapedto at least approximately follow said recesses or projections.

The field shaping collar 7 is surrounded by at least one winding 8 andas shown on FIG. 2 the ends of the winding or of each winding areconnected to a pulse generator for example to the two plates of acapacitor battery 9 respectively. Further, a switching component 10 isprovided, for example a fast circuit-breaker which can be composed of anelectronic device, said circuitbreaker being mounted in series betweenthe capactor battery 9 and winding 8. To charge the capacitors 9, apower transformer 11 is provided, the primary winding thereof being fedby mains 12.

The unit comprising the fields shaping collar 7 and winding 8 is mountedon a support 13 which delimits a supporting bed 14 on the top of whichis put a waterbox, in the present case the box 6, with reference toFIG. 1. This bed is designed to keep the water-box in a correct positionin relation with the shaping collar 7.

In the example shown, the shaping collar is provided on wall 7a thereof,with a thin rim 15, for example made of synthetic material such aspolytetrafluoroethylene or polyamide, said rim delimiting at the lowersection thereof, a flange 15a used as a stop for a belt 16 centered bysaid rim 15. The belt 16 is made of magnetically responsive, electricconductive material, for example aluminum, copper, brass or steel. Thisbelt has also a similar shape as the collector and water-box to beslipped onto the latter.

From above it is noticed that in the described embodiment, the belt 16is installed into rim 15, the waterbox 6 is installed and is centered bysaid belt 16 and kept at a suitable level by bed 14, then the radiatorcore is installed in such a way that the collector 4 thereof rests onthe waterbox 6 while being centered by belt 16.

These operations being performed and in supposing that the capacitorbattery 9 has already been charged, only the circuit-breaker 10 has tobe turned-off, which causes the discharge of the capacitors into thewinding 8 thus generating in collar 7 and belt 16 the induction of eddycurrents and a radial field which causes the sudden warping of the belt16 in the areas not resting on the collector 4 and the water-box 6, thussaid belt is set on the collector and the water-box, as shown in 16a, atthe upper section of FIG. 1.

In order that the above described crimping or clamping operation willensure the tightness between the collector and the water-box, manypossibilities can be contemplated. For example, as shown in FIG. 3, thewaterbox 6a can be made ofa relatively flexible material, for example ofelastomere, and provided with a marginal flange 18 on which the belt 16is set at the same time as on a moulding 19 of collector 4 which can inthat case be metallic. If the collector is made of electric conductivemetal, this is for example made of brass, aluminum or steel, then it isthe collector 4a (FIG. 3a) which can form a belt 16a on the periphericedge thereof, said belt 16a being then set onto the marginal flange 18of water-box 6a. The warping of belt 16 by an electromagnetic effect asdescribed above occurring in a very short period of time of about 50milliseconds, it has been noticed that the metal of the belt, during thewarping thereof, was acting like a fluid and that it could be extendedin some sections and contracted in some other. Consequently, themarginal flange 18 of the water-box, as shown in FIG. 4 for a collector6b, can be provided with projects which are wrapped by the belt 16 asshown in 16,.

Also the FIG. 4 shows that it is possible to place, between collector 4and water-box 6b, a gasket 20 which can be made of soft material or ofglue.

As already mentioned, the water-boxes can be made of metal without anyprejudice. This is shown on FIG. 5 on which the water-box is designatedby 60 while the belt 16a is directly shaped by collector 4a as shown onFIG. 3a.

The invention can be embodied in the same way for other types ofexchangers and FIG. 6 illustrates an example in which the exchanger iscomposed ofa core of tubes Ia contained in an envelope 21, said tubesrunning into collector-plates 22 which are covered by end flanges 23forming feeding boxes. A belt 16b, made of conductive metal is thensimultaneously used as a connection between the envelope 21, thecollector-plate 22 and the end flange 23. From this figure it is noticedthat the field causing the warping of belt 16b has for its effect todelimit in the latter, a groove 24 when care is taken to provide thecollector plate 22 with a diameter smaller than the one of the envelope21 and flange 23; this is used as a mark if it becomes necessary to sawsaid belt 16b to disassemble the unit.

Particularly when the water-box, as the one designated by reference 6din FIG. 7, is made of material which can be warped even temporarilyduring the setting operation or when the material of the water-box showssome brittleness, it is then advantageous that the lower surface 25 ofthe marginal flange 18 thereof delimits a housing 26 the collector 4b isat least partially embedded with also eventually a seal 27. Thus whenthe belt is warped whereby causing the setting of the unit, thecollector 4b cooperates with the water-box to form a very strong hollowgirder, whereby preventing any temporary warping of said water-box.

It has been noticed that the belt 16c is thus better applied on all thesections of the water-box and collector that it has to fit on, and theresult is that the seal 27 is strongly compressed. This ensures anassembling of a very good holding and a perfect tightness.

FIG. 8 shows a development of FIG. 7 according to which the collector 4bis also embedded in an housing of the water-box 18 and besides, saidfigure shows that it is sometimes advantageous to also provide aperipheric groove or spaced-out recesses 28 in the lateral edge ofmarginal flange 18 of the water-box 6e.

As mentioned above, a seal 29 can be placed between the collector andthe water-box and, for example, said seal can be shaped as representedin FIG. 8.

At the moment of the warping of belt 16d the latter penetrates into thegroove or into housings 28 while getting folded beneath the water-boxand collector. This embodiment ensures an extremely intimate joint ofthe two parts to be connected together, while making rigid the peripheryof the belt due to the fact of the warping 16d, that said belt has tosustain in order to fit at least partially on the groove or housings 28.

FIGS. 9 to 11 illustrate a development of the invention providing a verygood rigidity of the belt (then designated by 162) when put into placeand further causing said belt to exert a permanent resilient pressure onthe water-box 6f and on collector 4c. For that purpose the water-box 6fis provided at least at the four angles thereof with projecting ribs 30the section of which is increasing from top to bottom of the water-box,these ribs presenting for example a rounded outline as shown on FIG. 10.At the moment of the warping sustained by belt l6e through action of theelectromagnetic field developed from the discharge current, the twolateral sides 16, and 16 of the belt l6e are folded above the top ofmarginal flange 18 of the water-box and under the collector 4c which is,preferably, embedded as in FIGS. 7 and 8.

Because of the presence of ribs 30, the side 16, comes to a stop againstsaid ribs; this increases the elongation to which the side 16, issubjected during the warping thereof.

In that case it is noticed that said side 16, is only submitted to anelongation but no one of the sections thereof is submitted to acontraction. The result is that the metal delimiting the side 16, staysunder strain when folded, that makes the water-box be always applied onthe top of the collector. Relating to side 16 it has been noticed thatthe same result could be obtained if the ribs 30 were extended beneaththe collector and that anyway a similar result could still be obtainedeven without extending said ribs. In fact, in that case, and by suitablysetting the power of the shaping pulses, said side 16 get folded asshown in FIGS. 10 and 11 forming at the angles of the belt a warped fold31 which constitutes a kind of rib causing the metal of side 16 to bealso kept strained and also rendered more rigid because of the presenceof said folds 31.

According to FIGS. 11 to 13, to assemble each col lector 3 to eachwater-box 5, a belt 16f is utilized and the water-box S is supported bya bed 14 while the belt 16f centered by the water-box and the collectoreventually rests on a projected flange 14a of bed 14.

The field shaping collar 7, is made up in the form of a single windingfor example made of copper with beryllium having a shape correspondingto the one of belt 16f.

To allow the application of an electrical pulse designed to generate,from the winding formed by the shaping collar 7 electromagnetic forcesensuring the shaping of belt 16f, said single winding 7 is, for example,formed from a strip the ends thereof 32, 33 are fastened up on aninsulating core 34 and also on feeding conductors 35 connected to thepulse generator which comprises the capacitors 9, transformer 11 and theelectric current line 12.

The collar 7 is advantageously electrically insulated for example it isput into a thin insulating envelope and except for the core 34 to whichit is connected, it is freely mounted on the top of flange 14a of bed 14to be able to become out of shape or distorted at least in some of thesections thereof when it is run through by the discharge current of thecapacitors 9.

Accordingly during the warping that it sustains under the influence ofthe mutual electromagnetic repulsion generated between itself and thebelt 16f at the moment of the discharge of capacitors 9, said shapingdevice tends to become rounded in the linear sections thereof, orpresents a large radius of curve, whereby resulting in bringing togetherthe sections thereof having a small radius of curve to the angles ofbelt 16fand consequently in increasing the setting pressure in thoseareas where it has been deemed necessary to dispose of a more importantforce.

The warping of collar 7, can also be controlled and as shown in FIG. 13,support edges 36 or resilient blocks can be designed in some areas ofthe periphery thereof, which allows to accurately check the forcesapplied on the belt l6f whereby causing the setting thereof. Thus it ispossible as also shown in FIGS. 13 and 14 to fold at l80 the edge 16f,of said belt in order to pinch the turned-down edges of mutual centering5,, 3, formed by the water-box 5 and the collector 3 respectively whilethe other edge l6f is folded at right angle on a peripheral supportsection of the water-box 5, ensuring a great strength to the finishedassembling.

FIG. 14 illustrates an embodiment in which the shaping collar comprisesseveral superposed single windings 7 7,,,,..7,, which are respectivelyconnected to separate generators or to separate generators or toseparate outputs of a same generator whereby the electrical pulseapplied to each single winding can be adjusted. Through that way it ismoreover possible to vary the forces applied to the different zones ofthe belt 16f, for example a more important force can be applied fromsingle winding 7 to cause the folding of edge 16f only from belt 7 toavoid any warping of the turned-down edges of the collector andwater-box, while a strength of intermediary importance can be generatedfrom single winding 7, to ensure the folding of edge l6f The inventionis not rectricted to the embodiments shown and described in detail forvarious modifications thereof can moreover be applied to it withoutdeparting the scope of the invention. Particularly, the rim 15 can beremoved when the belt is directly formed by the collector. Also thecapacitor working in relaxation can be replaced by various pulsegenerators as by electronic generators rendering eventually possible tosuccessively apply several pulses to complete shaping of belt 16.

I claim:

1. Apparatus for securing together two abutting parts by anelectro-magnetically responsive and deformable clamping stripsurrounding and spanning the abutting portions of such parts,comprising:

eleetro-magnetic force producing collar means to be positioned insurrounding relation to said strip and abutting part portions; saidcollar means being resiliently distortable from a rest configurationconforming with said strip to a distorted energized configuration;

a pulse power generator, and

means electrically connecting said generator to said collar means toenergize said collar means to cause the latter to move from its restconfiguration to its energized configuration such that unequal forcesare applied about the periphery of said strip to magneto-form said stripinto clamping relation with said abutting part portions.

2. Apparatus according to claim 1 wherein said collar means has spacedend portions, and said connecting means is electrically connected toboth said ends.

3. Apparatus according to claim 2 wherein said collar means comprises aplurality of independent collars in juxtaposed relation and eachindependently connected by said connecting means to said generator.

4. Apparatus according to claim 3 wherein said generator has a pluralityof pairs of power outputs, said connecting means connecting each pair ofoutputs to one only of said collars, whereby each collar may beenergized with a selectively different power.

5. Apparatus according to claim 4 comprising means for adjusting theresiliency of at least a portion of at least one collar.

6. Apparatus according to claim 5 wherein said collar is rectangular inconfiguration said rest and said adjusting means comprises resilientpressure members engaging the elongate portions of said collar.

7. Apparatus according to claim 1 comprising means for adjusting theresiliency of said collar means.

8. Apparatus according to claim 7 wherein said collar means isrectangular in configuration said rest and said adjusting meanscomprises resilient pressure members engaging the elongate portions ofsaid collar means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. I3,805, DATED 3 April 23, 1974 INVENTOR(S) Andre Ghartet It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Address: Asnieres France Signed and fieaicd this thirtieth Day ofSeptember 1975 [SEAL] ANGUS RUTH C. MASON C. MARSHALL DANN ArrestingOfficer (mnmissiuncr nj'ialenls and Trademark-x

1. Apparatus for securing together two abutting parts by anelectro-magnetically responsive and deformable clamping stripsurrounding and spanning the abutting portions of such parts,comprising: electro-magnetic force producing collar means to bepositioned in surrounding relation to said strip and abutting partportions; said collar means being resiliently distortable from a restconfiguration conforming with said strip to a distorted energizedconfiguration; a pulse power generator, and means electricallyconnecting said generator to said collar means to energize said collarmeans to cause the latter to move from its rest configuration to itsenergized configuration such that unequal forces are applied about theperiphery of said strip to magneto-form said strip into clampingrelation with said abutting part portions.
 2. Apparatus according toclaim 1 wherein said collar means has spaced end portions, and saidconnecting means is electrically connected to both said ends. 3.Apparatus according to claim 2 wherein said collar means comprises aplurality of independent collars in juxtaposed relation and eachindependently connected by said connecting means to said generator. 4.Apparatus accordiNg to claim 3 wherein said generator has a plurality ofpairs of power outputs, said connecting means connecting each pair ofoutputs to one only of said collars, whereby each collar may beenergized with a selectively different power.
 5. Apparatus according toclaim 4 comprising means for adjusting the resiliency of at least aportion of at least one collar.
 6. Apparatus according to claim 5wherein said collar is rectangular in configuration said rest and saidadjusting means comprises resilient pressure members engaging theelongate portions of said collar.
 7. Apparatus according to claim 1comprising means for adjusting the resiliency of said collar means. 8.Apparatus according to claim 7 wherein said collar means is rectangularin configuration said rest and said adjusting means comprises resilientpressure members engaging the elongate portions of said collar means.